Optical drive apparatuses generally include audio disk drives, minidisk drives, compact disk drives, compact disk ROM players and the like. All such devices have a disk drive mechanism and an optical pickup device for irradiating a signal recording surface of an optical recording medium to read and write data relative to the recording surface. The pickup device is provided with an objective lens drive for driving an objective lens in focusing and tracking directions, such that a light beam is correctly focused on the recording surface of the medium and follows the recording track. Japanese patent publications Nos. 64-52234, 64-46232 and 01-91330 disclose various types of objective lens drives with hinges, wires and spring plates, respectively. Each such device has respective advantages and disadvantages.
The spring plate drive includes a spring plate formed by a thin treated metallic plate surface or a laminated metal member with adhesive for imparting attenuation. It has been considered difficult to determine how to impart good attenuation. Additionally, mounting or bonding of the spring plate member to an objective lens holder or base is critical. An attempt has been made to minimize the quantity of bonding adhesive to be employed during bonding, since the bonding adhesive may deform the member or cause various other difficulties.
The known spring plate-the drive requires about three to eight plate meters for driving in the focusing and tracking directions. This presents problems in terms of cost of materials and complexity of assembling operations.